Fold-away wrench set

ABSTRACT

There is disclosed a fold-away wrench having a wrench head ( 9 ) pivotally mounted on a handle ( 2 ). The wrench head ( 4 ) is an open flexible ring socket ( 3   a ) locatable over a fastener such as a nut, bolt or screw to move it. Pins ( 17 ) are provided for engagement with the wrench head ( 4 ) to close the wrench head over a fastener to be moved. Preferably, the wrench head ( 4 ) is pivotable on an axis pin ( 10 ) at one end of the socket ring while at the other end of the socket ring is a fulcrum pin ( 17 ) for closing the socket over the fastener.

FIELD OF INVENTION

This invention relates to a fold-away wrench or spanner. Wrenches orspanners as they are known in Great Britain are used for the purpose oftightening or slackening nuts, bolts or screws (hereinafter referred toas a fastener).

BACKGROUND TO THE INVENTION

The head portion of a ring wrench usually has an inner shape and sizecomplementary to that of a typically hexagonal or square fastener head.The head of such a wrench has an inner surface which surrounds thefastener head with only a small amount of play between the inner surfaceof the wrench and the fastener head. As torque is applied to the wrenchthe torque is transmitted to the fastener head to turn the fastener inthe appropriate direction.

Ring type wrenches are preferably to open jaw type wrenches because thetorque applied to the wrench is transmitted to the fastener via a muchlarger contact area and the ring head of the wrench if closed cantransmit far greater torque without harmful distortion of the fastenerhead and less chance of the wrench slipping off the fastener. Ringwrenches are however made to fit complementary fastener head sizes. Evenif the inner ring wrench head surface is appropriately shaped only asmall variation in size is possible between fastener head and the innerring wrench head surface. Accordingly, wrenches are normally supplied insets, for example a set of wrenches capable of use on the most commonfastener sizes of say 10–19 mm would consist of 10 different wrench headsizes as well as the near equivalent imperial or metric sizes wouldconsist of a further 5 Whitworth or B.S.P. sizes and 8-Inch A/F sizes.

Good quality wrench sets are quite easy to obtain and in useindividually selected ones of the sets are found as necessary and usedwith the appropriately sized head of a fastener. When a fastener ofanother size is used the first wrench is discarded and anotherappropriately sized wrench is used. When a number of the wrenches arebeing used there is a tendency for the user to mislay a wrench sizethereby extending the time and hence cost of completing a particularwork task.

It is an object of the present invention to substantially alleviate theabove mentioned disadvantages.

SUMMARY OF THE PRESENT INVENTION

According to the present invention there is provided a fold-away wrenchincluding a handle and a wrench head mounted on the handle for pivotalmovement relative thereto, the wrench head comprising an open flexiblering socket for engaging a fastener to be moved and means being providedon the wrench for closing said open flexible ring socket about afastener when the handle is turned in a predetermined direction, thewrench head being pivotable from a storage position within the handle toan operative position extending outwardly of the handle.

In one preferred embodiment in accordance with the present invention theopen flexible ring socket is pivotally mounted on an axis pin on thehandle on one open side of the socket and a fulcrum pin is engageablewith the opposite open side of the flexible ring socket for closing thesocket over a fastener. Preferably, the axis pin and the fulcrum pin arealigned along a line parallel to the longitudinal axis of the handle.The fulcrum pin is preferably the outermost pin relative to the centreof the handle and is conveniently movable with the axis pinlongitudinally of the handle.

The wrench preferably comprises a slot in the handle along which thefulcrum pin and axis are slidable. The slot is conveniently of aconstant width along its length. However, in an alternative embodimentthe slot comprises a bulbous inner end relative to the length of thehandle, of a diameter greater than the width of the slot. In the latterembodiment the slot preferably comprises two opposed concave recessesalignable with the axis pin when the fulcrum pin engages the outermostend of the slot remote from the bulbous end.

Preferably, the axis pin and fulcrum pin are each cylindrical andinclude regions of diametrically opposed planar surfaces. Thecylindrical surfaces of the axis pin preferably correspond to thediameter of the bulbous end of the slot and opposed recesses so that theaxis pin can rotate therein.

The diametrically opposed planar surfaces of the axis pin preferably arespaced by an amount corresponding to the width of planar side walls ofthe slot so that the axis pin is slidable in the slot with the planarsurfaces of the pin aligned parallel to the planar side walls of theslot. Preferably, the opposed parallel planar surfaces of the axis pinextend the whole length of the axis pin.

The opposed parallel planar surfaces of the fulcrum pin may extend overa portion of the length of the fulcrum pin from each end thereof, anintermediate space between the two said planar surface portionscomprising a cylindrical formation.

The wrench head may comprise two interconnected open flexible ringsockets together pivotable about the same axis pin. There may be twointerconnected ring sockets, one located at each end, respectively, ofthe handle for movement relative thereto. Preferably, each pair ofinterconnected flexible ring sockets comprise sockets of differentsizes.

Conveniently, each open flexible ring socket comprises an arm extendingoutwardly from an open end thereof for connection to the axis pin, and afreely movable arm extending from the other open end of the flexiblering and being engageable with the fulcrum pin for movement towards thefirst mentioned arm to close the socket around a fastener to be moved.Preferably, wherein the wrench head comprises a single open flexiblering socket mounted on a pivot for pivotal movement relative to thehandle. The wrench may comprise a pair of single open flexible ringsockets, one socket located at each end, respectively, of the handle forpivotal movement relative to the handle.

Alternatively, the wrench may comprise a pair of single open flexiblering sockets mounted on either side of a central plate, one socket ofeach pair of sockets being located at each end, respectively, of thehandle.

Therefore, there is provided an improved ring wrench whereas one wrenchhead is designed to enable torque to be conveniently applied to fitseveral sizes of fasteners. For example, one single wrench head can bemade to fit 12, 13, 14 mm sizes ½, 9/16 inch A/F sizes and ¼ B.S.P. orequivalent Whitworth imperial sizes of fastener head. The wrench headpreferably can be part of a set of wrenches conveniently presented in afoldaway or pocket sized package wherein the wrench holder or operatinghandle contains the required set or wrench heads. The wrench head isarranged to pivot around an axis on the handle until engaging a stop. Ifthe wrench head is applied to an appropriate sized fastener and a forceis applied in the appropriate direction, the wrench head will rotatearound the axis pin incorporated in the handle until the free arm of thewrench head comes into contact with the stop/fulcrum pin alsoincorporated in the handle. As torque is applied to the handle and thewrench head a turning force is applied to the fastener. The greater thetorque required to turn the fastener the greater the force acting on thefree arm of the wrench head against the fulcrum pin. This force betweenthe fulcrum pin and the free arm of the wrench head closes the gapbetween the free arm and the fixed arm of the wrench head closing theinner wrench head surface around the fastener and greatly increasing thegrip on the fastener. The wrench head will continue to resilientlyconstrict around the fastener until either the fastener turns or thefastener size prevents the wrench head from constricting any furtherrequiring use of another near sized wrench socket to be operated withoutdamage to the fastener. Because the metal of the resilient ring of thewrench head is being pulled around the fastener head from the free endto the fixed end it is inherently stronger than known ring wrench heads.The fold-away wrench of the present invention is essentially a onedirectional device (operation in the opposite direction requires thatthe handle be rotated 180° about its longitudinal axis). The innerwrench head surface can be profiled to enable maximum leverage betweenthe wrench head and fastener yet allowing a greater amount of fastenersizes to be accommodated. When a generally internal polygonal surface ofa wrench head socket is operated, the turning effect is greatest at thepoint nearest the corners of the polygonal surface but only those in thedirection in which the required rotation occurs. No torque whatsoever istransmitted through the opposite corners. Therefore, the inner wrenchhead surface needs only to act on the half of each flat of the polygonalsurface which is in the direction of torque applied enabling the profileof the present inner wrench head surface to be shaped so that contactbetween fastener and inner wrench head surface is only made in thedirection of the torque applied enabling greater diversity of sizes offastener heads to be used with any one wrench head socket.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described by way ofexample with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a fold-away wrench with a wrench headarranged to swivel out of a handle;

FIG. 2 is a perspective view of a fold-away wrench with the wrench headpivoted out of the handle and engaging a fastener;

FIG. 3 is a perspective view of the fold-away wrench of FIGS. 1 and 2with the wrench heads located for compactness within the handle;

FIG. 4A is a side elevational view of a first wrench head used in thewrenches of FIGS. 1 to 3;

FIG. 4B is a side elevational view of a second wrench head used in thewrench of FIGS. 1 to 3;

FIGS. 5( a) to (g) together show an expanded front elevational viewillustrating the component parts of the wrench and the movement of thewrench heads relative to the handle;

FIG. 6 is an enlarged front elevational view of part of the wrench headof FIG. 4A illustrating the transmission of torque between the wrenchhead and a fastener;

FIG. 7 is a perspective view similar to FIG. 3 illustrating analternative embodiment of the wrench in accordance with the presentinvention;

FIGS. 8( a) to (k) together show an expanded front elevational view ofthe wrench of FIG. 7 illustrating individual component partsindividually and assembled together;

FIGS. 9( a), (b) and (c) are each perspective views of the wrench ofFIGS. 7 and 8 each illustrating a different operational position of onewrench head;

FIGS. 10( a), (b) and (c) are each perspective views corresponding toFIGS. 9( a), (b) and (c), respectively, illustrating the manner in whichthe wrench heads slide and pivot in grooves in side plates constitutingthe handle of the wrench; and

FIGS. 11( a), (b) and (c) are each front elevational views illustratingdifferent embodiments of a fold-away wrench of the present invention

DESCRIPTION OF PREFERRED EMBODIMENTS

The embodiments described herewith will be described with reference toFIGS. 1 to 6 or FIGS. 7 to 10 or FIGS. 11( a), (b) and (c). Throughoutthe drawings like parts will be referred to by the same referencenumerals.

FIG. 1 illustrates an elongate wrench (1) comprising a handle (2)supporting two pivotal wrench heads (3,4), one at each opposed end (5,6)of the handle (2).

The handle (2) comprises two overlying elongate parallel spaced plates(7,8) having an elongate axis (9). The wrench heads (3,4) are eachmounted between the plates (7,8) for pivotal movement about a respectiveaxis pin 10. An elongate slot (15) is located at each end of each plate(7,8) so that the slots in each plate overlie each other at respectiveends of the plates. The axis pin (10) at each end projects through eachpair of slots respectively, and is terminated in a slidable plate (16)on either side of the handle so that the wrench heads while pivotableare also each movable backwards and forwards along the longitudinal axis(9) of the handle.

A further pin, a fulcrum pin (17), is located adjacent the axis pin 10and extends parallel to the axis pin (10) through a respective one ofthe pairs of slots (15) and is terminated in plates (16) on opposedsides of the handle (2) so as to be movable with the axis pin.

Each wrench head is provided with two flexible split ring sockets (3 a),one at each of two opposed ends of the wrench head. A fixed bridge (3 c)interconnects the two remote sockets of the wrench head on one side ofthe split in each socket. Each socket has an inner polygonal wrench headsurface (3 b). The sockets (3 a) are each provided on the opposite sideof the split with a resilient tongue (3 d) having a concave recess (3 e)at a free end thereof which in use engages the fulcrum pin (17) as willbe hereinafter described. A gap (3 g) extends from socket inner surface(3 b) between the bridge (3 c) and tongue (3 d) and as will be describedbelow is effective for closing the socket.

When the wrench is not in use, both wrench heads (3,4) will usually bestowed in the handle (2) in the manner shown for wrench head (4) inFIG. 1. Both wrench heads operate in the same manner and in thisdescription the movement of wrench head (3) only will be described inmore detail to illustrate the operation of the wrench from the closedposition shown in FIG. 5 f to the open position shown in FIG. 5 g. Otherwrench heads disclosed herein each operate in the same or similarmanner.

To prepare the wrench for use, a selected wrench head, say the wrenchhead (3), is initially pushed from one side of the handle (2) or theother side until the position shown in FIG. 1 is obtained. Theparticular size of socket to be used is chosen, say the top socket (3 a)in FIG. 1, and with the wrench head extending in a lateral directionrelative to the handle, the plates (16) together with the axis pin (10)and fulcrum pin (17) are slid along the slot (15) from the inner mostposition shown in FIG. 1 to the outermost position as illustrated inFIG. 2. The wrench head (3) is then pivoted around axis pin (10) untilit is in the position shown in FIG. 2 and as more clearly illustrated atthe top of FIG. 5 g.

This latter position of the wrench head (3) is more clearly illustratedin the enlarged views of FIGS. 4A and 4B. In the position shown in FIG.4A the wrench head (3) has been pivoted about axis pin (10) and as itdoes so the convex recess (3 e) at the head of the flexible tongue (3 d)of a selected one of the split ring sockets engages the fulcrum pin(17). The wrench tool is then ready for use and in the condition shownin FIG. 2.

When torque is applied in the clockwise direction D to grip the fasteneras shown in FIG. 2, a force couple is established between the fulcrumpin (17) and the axis pin (10) and this forces the tongue (3 d) to moveto close the gap (3 g) between the tongue and bridge (3 c), thereby totighten the ring (3 a) on the fastener. The more torque that is appliedto the handle (2), the stronger will be the grip of the ring (3 a) uponthe fastener, and the less likely will it be that the wrench will slip.

As the force on the handle is removed to release the grip of the ring (3a) on the fastener, so the spring resilience in the ring (3 a) re-opensthe gap (3 g) and the ring (3 a) is able to be rotated about thefastener in an anti-clockwise direction for repositioning of the handleof the wrench prior to giving it a further clockwise turn so as furtherto move the fastener.

When the work on the fastener is completed, the respective split ringsocket is removed from the fastener and the wrench head is pivoted aboutaxis pin (10) so that it again extends transversely to the handle (2).The plates (16) and the pivot and fulcrum pins (10) and (17) and thewrench head are then pushed along slot (15) to its innermost positionwhereupon the wrench head (3) may be pivoted into the stored positionshown in FIG. 3.

Two fixed locking pins (20,21) are provided internally on at least oneof the handle plates to act as detents to prevent the wrench heads (3,4)pivoting out from the handle as shown in FIG. 5 f, unless firmly pushedout from that position. Other detent means, for example of a sprung balltype, could alternatively be provided.

Each socket can be used with a number of differently sized fasteners,the resilience of the socket rings and the width of the gaps (3 g)providing this facility, and the four differently sized sockets providedon the wrench enable it to handle a wide range of different fastenersizes. A single wrench as above described can be capable of handlingcommon fastener sizes of say 6 to 19 mm, the near equivalent imperialsizes or metric sizes, Whitworth or B.S.P. sizes and 8-inch A/F sizes.

As shown most clearly in FIG. 6, in a wrench in accordance with theinvention, the inner surface (3 b) of the wrench socket is preferably ofa generally hexagonal shape but with convex bearing surfaces (22) whichare concave at their ends (23), where they interconnect. This avoidsexcessive reliance upon the edges of a hexagonal fastener for developingturning force.

FIGS. 7 to 10 illustrate a different embodiment of the invention whichis constructed and operates in a similar manner to the embodimentsdescribed above in regard to FIGS. 1 to 6. Accordingly the descriptionwhich follows refers only to those parts of the wrench which are notdisclosed in the embodiments described above.

The substantive difference between the wrench described above and thewrench of FIGS. 7 to 10 lies in the construction of the slots (15), andof the axis and fulcrum pins (10,17).

Each slot (15) in the embodiment of FIGS. 7 to 10 has, at its innermostend (30) with respect to the handle (2), a bulbous end (31) having anincreased width relative to the lateral width of the elongate slot (15).A second region (32) of increased width of the slot (15) is providedspaced from the bulbous end (31), approximately three quarters of theway along the length of the slot (15) from the bulbous end (31) towardthe outermost end of the slot. The increased width of the slot (15) atthe second region (32) is provided by opposed concave recesses (33) inslot walls (34).

The various views of FIG. 8 in particular show a view of the wrenchexploded into its individual parts. The axis pin (10) and fulcrum pin(17) are shown in detail at FIGS. 8( i) and (8 j). The axis pin (10) isin essence a cylindrical pin having a cylindrical surface (34) of adiameter corresponding to the diameter of the bulbous end (31) and therecessed area (32) which are of the same diametric width. The axis pinis also provided with diametrically opposed flat planar surfaces (35)which extend the whole of the axial length of the pin. The width betweenthe diametrically opposed surfaces (35) corresponds substantially to thewidth of the slot (15) between opposed planar wall surface (34) thereof.

The fulcrum pin (17) is also a cylindrical pin of the same length anddiameter as the axis pin (10), and has an external cylindrical surface(36). A central portion (37) of the pin (17) retains its cylindricalform. Each end (38,39) of the pin (17) has two diametrically opposedplanar surfaces (40) spaced by a distance substantially corresponding tothe width of the slot (15) between opposed planar wall surfaces (34) ofthe slot.

Therefore, the cylindrical surfaces (34,36) of the axis and fulcrum pins(10,17), respectively, serve in the wrench of FIG. 10 to allow thewrench heads (3,4) to rotate with the axis pin (10) about its rotationalaxis, and the fulcrum pin provides a curved central portion (37) forengagement by the concave recess (3 e) of each tongue (3 d) of thewrench head (3,4) respectively.

Each wrench head has an aperture (41) which has a cross-sectional shapecorresponding to the cross-sectional shape of the axis pin (10) in FIG.8. Therefore, the wrench head and its axis pin (10) are interlocked onerelative to the other in the assembled wrench, and can only rotatetogether when located at the bulbous end (31) or the recessed region(32) of the slot (15).

As shown in FIG. 10 a, when the wrench is not in use and the wrenchheads (3,4) are located within the handle (2), the axis pin (10) locatesat the bulbous end (31) and its opposed planar surfaces (35) lietransverse to the slot (15) thereby preventing movement of the axis pinalong the slot (15). However, in this location the wrench head can berotated so that the opposed planar surfaces (35) align with the slot(15) and allow the wrench head to be slid lengthwise of the slot (15),as shown in FIG. 10 b. The wrench head (3,4) cannot be rotated in thisposition within the slot (15).

Once the wrench head is slid as far outwardly as the slot will allow andwith fulcrum pin (17) against the outer end of the slot (15), the axispin (10) is located between the recesses (33). The wrench head (3,4) andaxis pin (10) are then rotatable until the wrench head is located in theposition shown in FIGS. 9 c and 10 c. As is more clearly shown in FIG. 9c, the recess (3 e) of the tongue of the wrench head engages the centralportion (37) of the fulcrum pin (17). The wrench otherwise operates asdescribed above with reference to the embodiment of FIGS. 1 to 6.

Each of the axis pin (10) and fulcrum pin (17) has a central elongatethreaded aperture (42) (FIG. 8( g), 8(i) and 8(j)) in which screws (43)are located at either end of the pins and secured to slidable plates(16) in position on the external surfaces of the handle (2). A detentpin (18) also having a central elongate threaded aperture therethroughfor receiving further screws (43) therein serves to act as a detent forpreventing undue movement of the wrench heads in the stored positionwithin the handle (FIG. 7), and to hold the sides of the handle (2) inplace. The detent pin (18) is located to cooperate with a small recess(44) defined by a protrusion (45) on each flexible ring socket and theexternal surface of the flexible ring (3 a) to prevent rotation of thewrench head (3) in the storage position. When it is necessary to rotatethe wrench head, the head is released by applying a small amount ofpressure to force the protrusion (45) past the detent pin. The detentpin will also just be engaged by protrusion (46) when wrench head (4) isrotated clockwise in FIG. 7. A small additional pressure moves theprotrusion (46) past detent (18) so that the wrench head (4) can berotated to a position in which the planar surfaces of its axis pin (10)are aligned with the slot (15) as described for wrench head (3).

In other embodiments which have similarities in construction andoperation to the previously described embodiments, only the differencesare described below. Otherwise, the wrench operates in the same manneras described for the embodiments of FIGS. 1 to 6 and 7 to 10.

FIG. 11 a discloses a wrench having a central elongate plate (50) onwhich a pivotal wrench head (51) is mounted at one end thereof.

Only one wrench head is shown in FIG. 11 a for illustrative purposes.However, modified forms of this embodiment are shown in FIGS. 11( b) and11(c) and have more than one wrench head.

As shown in FIG. 11 a the wrench head (3) is mounted for pivotalmovement about an axis pin (10) which is fixed in position relative tothe central plate (7). A fulcrum pin (17) is similarly mounted in afixed position on the plate (7) adjacent the axis pin (10). A detent pin(18) is located centrally of the plate (7) to hold the socket/flexiblering (3 a) in a position overlying the plate by the pin engaging arecess (44) defined between protrusion (45) and the outer surface of theflexible ring (3 a).

Pressure is applied to wrench head (3) to pivot the head away from thedetent pin (18) outwardly from the central plate (7) until recess (3 e)at the end of flexible tongue (3 d) engages fulcrum pin (17). The recess(3 e) is of a size which requires a slight pressure to be applied to thesocket until the recess (3 e) clicks over the fulcrum pin temporarilylocking the socket in its operative position extending generallyoutwardly of the central plate in a direction substantially parallel tothe longitudinal axis of the central plate (7). The wrench (1) thenoperates in the same manner as described above with particular referenceto FIGS. 1 to 6, to tighten or slacken a fastener.

The embodiment in FIG. 11( b) is similar to the embodiment of FIG. 11(a) but has two wrench heads (3,4). Both wrench heads operate in the samemanner as the wrench heads disclosed above.

The embodiment of FIG. 11( c) is again similar in operation to theembodiments of FIGS. 11( a) and 11(b). However, in this case as shown inFIG. 11( c) two wrench heads are located on one side of central plate 7and two further wrench heads are located on the opposite side of plate 7making four heads on one wrench.

As previously mentioned, a wrench with four different sizes of socketenables use of the wrench with a very wide range of sizes of fastenerfrom say 6 to 19 mm as well as near equivalent imperial or metric sizes,and near Whitworth, B.S.P and A/F sizes.

There has thus been disclosed various embodiments of a wrench inaccordance with the present invention. These wrenches have theparticular additional advantage that in extreme conditions theresilience of the metal of the wrench head is such that the tongue (3 d)and the bridge (3 c) will contact each other closing the gap (3 g)therebetween. Such contact serves to protect the fastener from anyadditional forces being applied to it. Moreover, because in use theflexible ring is being pulled around a fastener, the wrench head isconsiderably stronger than known wrenches.

Preferably, the thickness of the resilient wrench head varies in alateral direction across the flexible ring (3 a), that is in a directionfrom tongue (3 d) to bridge (3 c), with the tongue being thinner thanthe bridge because the tension in the wrench head in use is greater inthe bridge than in the flexible tongue.

1. A fold-away wrench including a handle and a wrench head mounted onthe handle for pivotal movement relative thereto, the wrench headcomprising an open flexible ring socket for engaging a fastener to bemoved and means being provided on the wrench for closing said openflexible ring socket about a fastener when the handle is turned in apredetermined direction, the wrench head being pivotable from a storageposition within the handle to an operative position extending outwardlyof the handle.
 2. A wrench as claimed in claim 1, wherein the openflexible ring socket is pivotally mounted on an axis pin on the handleat one end of the socket ring and said closing means comprises a fulcrumpin engageable with the opposite end of the flexible ring socket forclosing the socket over a fastener.
 3. A wrench as claimed in claim 2,wherein the axis pin and the fulcrum pin are aligned along a lineparallel to the longitudinal axis of the handle.
 4. A wrench as claimedin claim 3, wherein the fulcrum pin is the outermost pin relative to thecentre of the handle.
 5. A wrench as claimed in claim 2, wherein thefulcrum pin and axis in are movable longitudinally of the handle.
 6. Awrench as claimed in claim 5, comprising a slot in the handle alongwhich the fulcrum and axis pins are slidable.
 7. A wrench as claimed inclaim 6, wherein the slot is of a constant width along its length.
 8. Awrench as claimed in claim 6, wherein the slot comprises regions ofincreased width along its length.
 9. A wrench as claimed in claim 8,wherein the slot comprises a bulbous inner end relative to the length ofthe handle, of a diameter greater than the width of the slot.
 10. Awrench as claimed in claim 8, wherein the slot comprises two opposedconcave recesses alignable with the axis pin when the fulcrum pinengages the outermost end of the slot remote from the bulbous end.
 11. Awrench as claimed in claim 8, wherein the axis in and fulcrum pin areeach cylindrical and include regions of diametrically opposed planarsurfaces.
 12. A wrench as claimed in claim 11, wherein the cylindricalsurfaces of the axis pin corresponds to the diameter of the bulbous endof the slot and opposed recesses so that the axis pin can rotatetherein.
 13. A wrench as claimed in claim 11, wherein the diametricallyopposed parallel planar surface of the axis pin are spaced by an amountcorresponding to the width of planar side walls of the slot so that theaxis pin slidable in the slot with the planar surfaces of the pinaligned parallel to the planar side walls of the slot.
 14. A wrench asclaimed in claim 11, wherein the opposed parallel planar surfaces of theaxis pin extend the whole length of the axis pin.
 15. A wrench asclaimed in claim 11, wherein the opposed parallel planar surfaces of thefulcrum pin extend over a portion of the length of the fulcrum pin fromeach end thereof, an intermediate space between the two said planarsurface portions comprising a cylindrical formation.
 16. A wrench asclaimed in claim 1, wherein the wrench head comprises two interconnectedopen flexible ring sockets together pivotable about the same axis pin.17. A wrench as claimed in claim 16, comprising two interconnected ringsocket sets, one located at each end, respectively, of the handle formovement relative thereto.
 18. A wrench as claimed in claim 16, whereinthe interconnected flexible ring sockets comprise sockets of differentsizes.
 19. A wrench as claimed in claim 2, wherein each open flexiblering socket comprises an arm extending outwardly from an open endthereof for connection to the axis pin, and a freely movable armextending from the other open end of the flexible ring and being engageable with the fulcrum pin for movement towards the first mentioned armto close the socket around a fastener to be moved.
 20. A wrench asclaimed in claim 1, wherein the wrench head comprises a single openflexible ring socket mounted on a pivot for pivotal movement relative tothe handle.
 21. A wrench as claimed in claim 20, comprising a pair ofsingle open flexible ring sockets, one socket located at each end,respectively, of the handle for pivotal movement relative to the handle.22. A wrench as claimed in claim 21, comprising a pair of single openflexible ring sockets mounted on either side of a central plate, onesocket of each pair of sockets being located at each end, respectively,of the handle.